School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, People's Republic of China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China.
J Neurophysiol. 2022 Jul 1;128(1):239-248. doi: 10.1152/jn.00091.2022. Epub 2022 Jun 29.
The perceived position of a moving object in vision entails an accumulation of neural signals over space and time. Due to neural signal transmission delays, the visual system cannot acquire immediate information about the moving object's position. Although physiological and psychophysical studies on the flash-lag effect (FLE), a moving object is perceived ahead of a flash even when they are aligned at the same location, have shown that the visual system develops the mechanisms of predicting the object's location to compensate for the neural delays, the neural mechanisms of motion-induced location prediction are not still understood well. Here, we investigated the role of neural activity changes in areas MT+ (specialized for motion processing) and the potential contralateral processing preference of MT+ in modulating the FLE. Using transcranial direct current stimulations (tDCS) over the left and right MT+ between pre- and posttests of the FLE in different motion directions, we measured the effects of tDCS on the FLE. The results found that anodal and cathodal tDCS enhanced and reduced the FLE with the moving object heading to but not deviating from the side of the brain stimulated, respectively, compared with sham tDCS. These findings suggest a causal role of area MT+ in motion-induced location prediction, which may involve the integration of position information. Perceived positions of moving objects are related to neural activities in areas MT+. We demonstrate that tDCS over areas MT+ can modulate the FLE, and further anodal and cathodal tDCS facilitated and inhibited the FLE with a moving object heading to but not deviating from the side of the brain stimulated, respectively. These findings suggest a causal role of area MT+ in motion-induced location prediction and contribute to understanding the neural mechanism of the FLE.
在视觉中，移动物体的感知位置需要在空间和时间上积累神经信号。由于神经信号传输延迟，视觉系统无法立即获取移动物体位置的信息。尽管关于闪光滞后效应（FLE）的生理和心理物理学研究表明，即使移动物体和闪光对齐在同一位置，移动物体也会被感知在闪光之前，这表明视觉系统已经发展出预测物体位置的机制来补偿神经延迟，但运动引起的位置预测的神经机制仍未得到很好的理解。在这里，我们研究了 MT+（专门用于运动处理的区域）中的神经活动变化以及 MT+的潜在对侧处理偏好在调制 FLE 中的作用。在不同运动方向的 FLE 前后测试中，我们在左、右 MT+上使用经颅直流电刺激（tDCS），测量 tDCS 对 FLE 的影响。结果发现，与假刺激相比，刺激物朝向大脑受刺激侧的阳极和阴极 tDCS 分别增强和降低了 FLE，而刺激物偏离大脑受刺激侧的阳极和阴极 tDCS 则增强和降低了 FLE。这些发现表明，MT+区在运动引起的位置预测中起着因果作用，这可能涉及位置信息的整合。移动物体的感知位置与 MT+区的神经活动有关。我们证明，MT+区的 tDCS 可以调节 FLE，并且进一步发现，刺激物朝向大脑受刺激侧的阳极和阴极 tDCS 分别促进和抑制了 FLE，而刺激物偏离大脑受刺激侧的阳极和阴极 tDCS 则促进和抑制了 FLE。这些发现表明，MT+区在运动引起的位置预测中起着因果作用，并有助于理解 FLE 的神经机制。
